Fixed length clamp assembly

ABSTRACT

The invention provides a clamp assembly for holding a set of seal elements to a rail, the assembly including an arm sub-assembly and a locking mechanism. The arm sub-assembly includes first and second arms which are pivotally attached by a pin. The first arm includes an elongate first link portion and a first engagement portion extending substantially transversely to the first link portion. The first engagement portion includes a first contact part which is adapted to engage a selected one of the set of seal elements. In addition, the second arm includes a second link portion and a second engagement portion extending substantially transversely to the second link portion. Also, the second engagement portion includes a second contact part adapted to engage another one of the set of seal elements.

CROSS-REFERENCE TO OTHER APPLICATIONS

This application claims the benefit of priority of U.S. Provisional Patent Application No. 61/021,445 filed Jan. 16, 2008, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The invention relates in general to clamp assemblies and more specifically to a fixed length clamp assembly for a rail.

BACKGROUND OF THE INVENTION

In the prior art, resilient rail seal elements are positioned on both sides of a rail in order to provide a relatively uninterrupted travel path for surface road traffic across the rail, to define a gap adjacent to the rail and to minimize fouling of the ballast by various materials. The rail seal elements need to be held in position, i.e., tightly held against the sides of the rail respectively.

Such prior art devices are generally adjustable, so that they may be used in various situations, and with rail seal elements having different configurations (i.e., different shapes and/or dimensions). However, the load applied to the rail seal elements by the known devices should be within an optimal range. For example, a clamping device which imposes a relatively small load would not succeed in holding the rail seal elements sufficiently tightly against the rail, resulting in unsatisfactory performance. Foreign material may then get between the rail seal elements and the rail, to push the rail seal elements out of position, or the rail seal elements may become disengaged from the rail and therefore interfere with traffic on or across the rails.

Also, it is possible for the prior art device to impose a load on the rail seal element(s) which is greater than the optimum range, thereby causing distortion, damage to or breakdown of the rail seal elements and/or the clamping device.

From the foregoing, it can be seen that the prior art devices have some disadvantages, and such disadvantages involve allowing for input or judgment of the installer as to the appropriate load. There is therefore a significant possibility that the prior art device will be improperly installed, especially if the installer is inexperienced or if working conditions are difficult.

Therefore, there is a need for an improved clamp assembly to hold rail seal elements against the rail.

SUMMARY OF THE INVENTION

In a broad aspect, the invention provides a clamp assembly for holding a set of seal elements to a rail, the assembly including an arm sub-assembly and a locking mechanism. The arm sub-assembly includes first and second arms which are pivotally attached by a pin. The first arm includes an elongate first link portion and a first engagement portion extending substantially transversely to the first link portion. The first engagement portion includes a first contact part which is adapted to engage a selected one of the set of seal elements. In addition, the second arm includes a second link portion and a second engagement portion extending substantially transversely to the second link portion. Also, the second engagement portion includes a second contact part adapted to engage another one of the set of seal elements.

The arm sub-assembly is movable between an assembled position and an unassembled position. In the assembled position, the first and second engagement portions hold the set of rail seal elements against the rail and the locking mechanism is engaged to hold the first and second arms substantially fixed relative to each other. In the unassembled position, the locking mechanism is disengaged, allowing the first and second arms to pivot relative to each other about the pin.

In another aspect of the invention, the locking mechanism can be a tube that is positioned at least partially around the arm sub-assembly.

In another aspect of the invention, the tube has a slot extending a predetermined distance from the first end toward the second end, and terminating at a stop portion. The slot permits movement of a part of the first engagement portion therein, to allow movement of the arm sub-assembly between the assembled and unassembled positions.

In yet a further aspect of the invention, an end of the tube is adapted to enable urging of the tube in a longitudinal direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood with reference to the attached drawings, in which:

FIG. 1 is a side view of an embodiment of a fixed length clamp assembly of the invention, in an assembled position;

FIG. 2 is a top view of the clamp assembly of FIG. 1 in the assembled position, with a portion of a tube thereof cut away;

FIG. 3 is a side view of the clamp assembly of FIG. 1 in the assembled position, engaged with rail seal elements on the sides of a rail;

FIG. 4 is a side view of the embodiment of the clamp assembly of FIG. 1, in an unassembled position; and

FIG. 5 is a side view of an embodiment of the clamp assembly wherein an end of the tube has been adapted to enable urging of the tube in a longitudinal direction.

DETAILED DESCRIPTION

Turning to FIGS. 1 and 2, an embodiment of a fixed length clamp assembly 20 of the invention is shown in an assembled position. As illustrated, the fixed length clamp assembly 20 includes a locking mechanism, such as a tube 22, and an arm sub-assembly 23 at least partially positioned therein. The arm sub-assembly 23 includes a first arm 24 and a second arm 26 which are pivotally attached by a pin 27. As shown in FIG. 1, the first arm 24 includes a first arm link portion 28, and the second arm 26 includes a second arm link portion 30. Preferably, the first arm 24 also comprises a first arm engagement portion 31, extending substantially transversely from the first arm link portion 28, and a first arm contact part 42. The second arm 26 comprises a second arm engagement portion 32 extending substantially transversely from the second arm link portion 30, and a second arm contact part 44. The tube 22 extends between a first end 34 and a second end 36, and includes a slot 38 extending a predetermined distance from the first end 34 towards the second end 36, to terminate at a stop portion 40. The slot 38 permits movement of a part, or portion 41 of the first arm engagement portion 31 therein as the arm sub-assembly 23 is moved between the assembled and the unassembled positions, as will also be described. In the assembled position, the first arm link portion 28 and second arm link portion 30 are substantially aligned and the tube 22 is positioned such that the second end of the tube 36 is abutting or nearly touching the second arm engagement portion 32. The tube 22 reduces or prevents pivoting of the first and second arms 24 and 26 at the pin 27 such that the first arm link portion 28 and second arm link portion 30 are held in a substantially fixed position relative to each other in the assembled position.

FIG. 3 illustrates an embodiment of the clamp assembly in the assembled position interacting with rail seal elements 11 and 12. The first and second rail seal elements 11 and 12 are made of a suitably resilient material and are specifically configured for use on predetermined sides 13 and 14 respectively of a rail 10. The first and second rail seal elements 11 and 12 have parts 15 and 16 at which the first and second arm contact parts 42 and 44 of the first and second arms 24 and 26 are intended to engage the first and second rail seal elements 11 and 12 to hold them in place against the rail 10.

It will be appreciated that the first and second arms 24 and 26 are formed and sized so that, when the arm sub-assembly 23 is in the assembled position, the first and second arm contact parts 42 and 44 are spaced apart from each other by a fixed distance “D”, thereby providing a fixed length clamp assembly. This results in lateral loading of the first and second rail seal elements 11 and 12 that can be determined in advance for a known type of rail seal element and type of rail.

The arm sub-assembly 23 is movable between the assembled position, in which the first and second engagement portions 31 and 32 hold the first and second rail seal elements 11 and 12 against the rail 10, and the unassembled position, in which the second arm 26 is pivotal about the pin 27 relative to the first arm 24.

FIG. 4 illustrates an schematic diagram of the clamp assembly in the unassembled position. When the arm sub-assembly 23 is moved relative to the tube 22 by at least a predetermined distance in the direction of arrow “A”, the first arm link portion 28 extends sufficiently beyond the second end 36 such that the pin 27 is positioned outside the tube 22, thereby permitting the second arm 26 to pivot about the pin 27.

Such relative movement can be achieved by movement of the tube 22 in the direction of arrow “B” relative to the arm sub-assembly 23, e.g. by urging the second end 36 of the tube 22. Movement of the arm sub-assembly 23 in the direction indicated by arrow “A” is assisted by the configuration of the slot 38, into which the part 41 of the first arm engagement portion 31 is receivable. Movement of the part 41 in the direction indicated by arrow “A” relative to the tube 22 is limited by the stop portion 40, when the part 41 of the first arm engagement portion 31 engages the stop portion 40.

FIG. 5 illustrates an embodiment of the clamp assembly in the assembled position wherein an end of the tube 22 has been adapted to enable urging of the tube in a longitudinal direction. The first end 34 of the tube 22 includes a cap 50 that extends beyond the edge of the first end 34. The cap 50 enables a device to catch the first end 34 and urge it in a longitudinal direction away from the second arm 26. For example, a rod could be used to lever the tube 22 by placing an end of the rod against the cap and using the first arm 24 as a fulcrum.

In use, the arm sub-assembly 23 is movable from the unassembled position to the assembled position by first aligning the first and second arm link portions 28 and 30, and then moving the arm sub-assembly 23 relative to the tube 22 in the direction indicated by arrow “B” in FIG. 4. Such relative movement can be achieved by movement of the tube 22, e.g. by urging the first end 34 of the tube 22, toward the pin 27. Preferably, the arm sub-assembly 23 is so moved until it is in the assembled position, as shown in FIG. 1. It will be understood that, as the arm sub-assembly 23 is moving to the assembled position, the second arm link portion 30 passes through the second end 36 and into the tube 22.

One procedure for mounting the clamp assembly on the rail and the rail seal elements 11 and 12 is as follows. The clamp assembly 20 in the unassembled position is inserted into and pushed through ballast (not shown) underneath the rail 10 and the rail seal elements 11 and 12. As shown in FIG. 3, this is generally done in the direction indicated by arrow “C” relative to the rail 10 and rail seal elements 11 and 12. The clamp assembly 20 is pushed into the ballast with the second arm 26 leading and then moved underneath the rail 10 until the assembly 20 is substantially transverse to the rail and the first and second arm contact parts 42 and 44 are substantially outside the rail seal elements.

At this point, the first and second arm engagement portions 31 and 32 are then rotated upwardly, so that the first and second arm link portions 28 and 30 are substantially aligned, the first and second arm engagement portions 31 and 32 are substantially vertical, and the respective first and second arm contact parts 42 and 44 are generally positioned to engage the parts 15 and 16 of the rail seal elements 11 and 12.

In order to lock the clamp assembly in the assembled position, the first end 34 is urged in the direction of arrow C. As noted above, this can conveniently be done with any suitable tool. This causes the tube 22 to move in the direction of arrow C, and pushes the second end 36 of the tube 22 against a corner part 48 of the second arm engagement portion 32. The first and second arm engagement portions 31 and 32 are thus forced to engage the rail seal elements 11 and 12. When the tube 22 is moved as far as possible in direction C, the clamp assembly 20 is in the assembled position. As the clamp has a fixed length, the force being applied to the rail seal elements is known and therefore pre-determined.

In order to cause the first and second arms to release the rail seal elements, the second end 36 of the tube 22 is urged or pried in the direction of first arm 24. The fixed length clamp assembly 20 can then be put into the unassembled position and removed, if desired.

From the foregoing, it can be seen that the fixed length clamp assembly is for use where the outer surfaces of the rail seals are spaced apart by a known distance, within a relatively small tolerance. The clamp assembly of the invention therefore enables a known load to be imposed on the rail seal elements, i.e., a load which is within the optimal range therefor, with minimal scope for input from the installer.

It will be appreciated by those skilled in the art that the invention can take many forms, and that such forms are within the scope of the invention as described herein. Therefore, the spirit and scope of the invention should not be limited to the descriptions of the preferred versions contained herein. 

1. A clamp assembly for holding a set of rail seal elements to a rail comprising: an arm sub-assembly including a first arm; a second arm; and a pin pivotally coupling the first arm and the second arm; and a locking mechanism; wherein the locking mechanism is operable to lock the first arm in a fixed length clamp assembly relative to the second arm to provide a predetermined force to hold the set of rail seal elements against the rail.
 2. The clamp assembly of claim 1, wherein the first arm includes a first arm link portion, a first arm engagement portion, and a first arm contact part; and the second arm includes a second arm link portion; a second arm engagement portion; and a second arm contact part, wherein the pin pivotally couples the first arm link portion and the second arm link portion.
 3. The clamp assembly of claim 2 wherein a first end of the tube surrounds the first arm link portion and a second end of the tube surrounds the second link portion when the assembly is in an assembled state; such that the tube is operable to fix the first arm in the fixed position relative to the second arm by simultaneously covering, at least partially, both the first arm link portion and second arm link portion.
 4. The clamp assembly of claim 3 wherein the tube further comprises a slot that extends longitudinally along the tube from a first end of the tube to a stop portion of the tube.
 5. The clamp assembly of claim 4 wherein the distance from the stop portion to a second end of the tube is greater than the length of the second arm link portion and less than the length of the first arm link portion.
 6. The clamp assembly of claim 4 wherein the slot receives the first arm engagement portion when the tube is slid relative to the first arm engagement portion.
 7. The clamp assembly of claim 2 wherein the set of rail seal elements comprises a pair of rail seal elements.
 8. The clamp assembly of claim 7 wherein the first arm contact part is adapted to engage one of the pair of rail seal elements, and the second arm contact part is adapted to engage a second of the pair of rail seal elements.
 9. The clamp assembly of claim 2, wherein the first engagement portion extends substantially transversely from the first link portion.
 10. The clamp assembly of claim 2, wherein the second engagement portion extends substantially transversely from the second link portion.
 11. The clamp assembly of claim 2, wherein an end of the tube includes an apparatus to enable urging of the tube in a longitudinal direction.
 12. The clamp assembly of claim 11 wherein the apparatus comprises a protrusion that extends away from the axis of the tube.
 13. A clamp assembly comprising: an arm sub-assembly including a first arm having a first arm link portion, a second arm having a second arm link portion, and a pin for pivotally coupling the first arm link portion to the second arm link portion; and a substantially straight tube, wherein the tube is operable to lock the first arm in a fixed position relative to the second arm to provide a fixed length clamp assembly to hold a set of rail seal elements against a rail.
 14. A system for providing a travel path across a rail for surface traffic and for minimizing fouling of ballast comprising a set of rail seal elements and a plurality of fixed length clamp assemblies, wherein the fixed length clamp assembly includes: an arm sub-assembly including a first arm having a first arm link portion; a second arm having a second arm link portion; and a pin for pivotally coupling the first arm link portion to the second arm link portion; and a substantially straight tube operable to lock the first arm in a fixed length clamp assembly relative to the second arm to provide a predetermined force to hold the set of rail seal elements against the rail. 